A father of two went to his local tobacconist and bought a $20 bag of Kronic so he could "have a smoke, chill out" and still pass his drug test at work.

That was three years ago and it's a decision he regrets to this day.

"I'll be honest, I was a marijuana smoker who could live normally, hold down a full-time job, but there were drug tests and I was failing them," the man, who asked not to be named, told the Mercury.

"It was around the time this synthetic stuff came out and you could get it down at your corner tobacco shop. To me it was like smoking marijuana but all of a sudden you get the effect of a trip," he said.

"It puts you in a psychosis, deep to the point where you've got to lay down and the room spins and spins.

"For someone like me who has tried drugs ... you've found what you are looking for. You are looking for a way out from whatever you're trying to escape."

But there was a catch.

"The synthetic stuff, it will only last about 10 minutes. You spike, you get a massive rush and then it goes away fairly quick as opposed to marijuana where you could be done for half a day.

"This stuff will blast you for 10 minutes, then you are back into it again. It's just so potent you feel it fry your brain."

The 43-year-old said the low cost was also a drawcard for the drug he came to depend on for a couple of years.

"A $20 dollar bag is like getting $50 worth of marijuana. So it's much cheaper but I knew it was something you really couldn't stay on full-time because it was just so strong. I knew it.

"This synthetic stuff really does fry you. It can make you hallucinate, that's for sure. Yet you could buy it in tobacco shops. Even now you can still get it from under the counter, no doubt about it."

The drug caused this dad a world of pain and he hopes sharing his story will stop others from experimenting.

"My life became unmanageable. I'd held down a job, been married for 14 years and I lost both of them through addiction," he said. "That all ended for me."

Now going through rehab, he is looking to the future and says "massive doors are starting to open".

Hopefully his teenage children will learn from his mistakes.

"These kids have seen a lot and at the end of the day I'm trying to say I hope they don't go down my path. I'm sure they won't because they've seen a lot thanks to me, but whatever I can do to prevent it, or stop anyone else, I will."

What your children need to know

Cannabinoids are chemicals found in cannabis that are unique to the plant. The most well known is THC (delta-9-tetrahydrocannabinol) – the substance primarily responsible for the psychoactive effects of cannabis.

Synthetic cannabinoids are functionally similar to THC and bind to the same cannabinoid receptors in the brain and other organs.

In recent years, a wide variety of synthetic cannabinoid products have become available as smoking mixtures sold on the internet and in various shops.

They are usually sold in foil sachets, typically containing 1gram to 3grams of dried plant matter to which one or more of the cannabinoids have been added.

A solution of the cannabinoids is sprayed onto the herbal mixture.

A number of plant-based ingredients are often listed on the packaging, but scientific testing has found that many are not actually present.

The chemicals used to create synthetic cannabinoids are constantly changing and often unknown.

The drugs are usually sold in coloured foil sachets and marketed with names such as K2, Spice, Kronic, Kalma, Northern Lights, Puff, Aroma, Magic, Dragon, Marley or Mango Kush. They are designed to have effects similar to cannabis when smoked.

Costing about $10 per 20 grams, each sachet contains enough for eight joints.